Among electric motors, which are one type of electric rotary machines, there is known a hybrid excitation flux switching motor (hereinafter also referred to as HEFSM). In the HEFSM, a stator includes both windings and permanent magnets. The HEFSM has an operating mode in which the magnetic flux of the permanent magnets flows from the stator to a rotor (see for example Patent Document 1). In the invention of Patent Document 1, predetermined windings (field windings) are in contact with some of permanent magnets. The conduction of direct current to the field windings is controlled to control the magnetic flux of the permanent magnets. In addition, AC power is supplied to the other windings (armature windings) for forming rotating magnetic field to rotate the rotor.